Mobile X-ray apparatus

ABSTRACT

A mobile X-ray apparatus includes: an X-ray radiation device configured to emit X-rays; a controller configured to control the X-ray radiation device; a power supply configured to supply operating power to the X-ray radiation device and the controller; and a charger configured to charge the power supply. The power supply includes a lithium ion battery including a plurality of battery cells, at least one current sensor configured to detect current of the lithium ion battery, and a battery management system (BMS) configured to detect an occurrence of an overcurrent in the lithium ion battery via the at least one current sensor in response to receiving an X-ray emission preparation signal, and to control an on-state or an off-state of a discharge current path in which a discharge current flows from the lithium ion battery to the controller and the X-ray radiation device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/961,502 filed Apr. 24, 2018, which is a continuation of U.S. patentapplication Ser. No. 15/370,679 filed Dec. 6, 2016, which claimspriority from Korean Patent Application No. 10-2016-0099133, filed Aug.3, 2016, in the Korean Intellectual Property Office. The disclosures ofabove-named applications are incorporated herein in their entireties byreference.

BACKGROUND 1. Field

Apparatuses and methods consistent with exemplary embodiments relate toX-ray apparatuses using a lithium ion battery.

2. Description of the Related Art

X-rays are electromagnetic waves having wavelengths of 0.01 to 100angstroms (Å), and are widely used, due to their ability to penetrateobjects, in medical apparatuses for imaging the inside of a living bodyor in non-destructive testing equipment for industrial use.

An X-ray apparatus using X-rays may obtain X-ray images of an object bytransmitting X-rays emitted from an X-ray source through an object anddetecting a difference in intensities of the transmitted X-rays via anX-ray detector. The X-ray images may be used to examine an internalstructure of an object and diagnose a disease of the object. The X-rayapparatus facilitates observation of an internal structure of an objectby using a principle in which penetrating power of an X-ray variesdepending on the density of the object and atomic numbers of atomsconstituting the object. As a wavelength of an X-ray decreases,penetrating power of the X-ray increases and an image on a screenbecomes brighter.

SUMMARY

One or more exemplary embodiments may provide a mobile X-ray apparatusincluding lithium ion batteries.

According to an aspect of an exemplary embodiment, a mobile X-rayapparatus includes: an X-ray radiation device; a controller configuredto control the X-ray radiation device; a power supply configured tosupply operating power to the X-ray radiation device and the controllervia a lithium ion battery and control overcurrent that occurs duringX-ray emission by the X-ray radiation device; and a charger configuredto charge the power supply.

The power supply may include: a battery management system (BMS)configured to detect a state of the power supply and control anoperation of the power supply; a discharge field effect transistor (FET)configured to control the overcurrent and including a plurality of FETsconnected in parallel; and a charge FET.

The discharge FET and the charge FET may be further configured tocontrol a path of a discharge current or a charge current when thelithium ion battery is discharged or charged.

The BMS may be further configured to detect the state of the powersupply and control a charge path and a discharge path by turning on/offthe discharge FET and the charge FET.

The BMS may be further configured to control an operation of aprotection circuit for protection against at least one ofover-discharge, overcurrent, overheating, and unbalancing between cellsin the lithium ion battery.

The power supply may further include a large-capacity current sensor anda small-capacity current sensor, and the BMS may be further configuredto detect, during the X-ray emission by the X-ray radiation device, theovercurrent by activating the large-capacity current sensor.

The mobile X-ray apparatus may further include a current sensor locatedat an output terminal of the charger in order to detect a chargecurrent.

The controller, the power supply, and the charger may each be embodiedin a different module.

The power supply may include a temperature sensor configured to detect atemperature within the power supply, and the controller may be furtherconfigured to directly monitor information about a temperature detectedby the temperature sensor.

The power supply and the charger may respectively include interrupt pinsthat can be directly controlled by the controller, and the controllermay be further configured to respectively turn off the power supply andthe charger via the interrupt pins.

The charger may be a wireless charging system composed of a transmittingmodule and a receiving module.

The charger may be further configured to receive power wirelessly fromthe outside and charge the power supply based on the received power.

The charger may be further configured to stop charging of the powersupply when a low current state, where a charge current is less than aspecific reference value, remains for a specific amount of time.

The charger may be further configured to restart the charging of thepower supply when a voltage of the lithium ion battery is lower than aspecific reference value.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects will become more apparent by describingcertain exemplary embodiments, with reference to the accompanyingdrawings, in which:

FIG. 1 is an external view and block diagram of an X-ray apparatus,according to an exemplary embodiment;

FIG. 2 is an external view of an X-ray detector included in the X-rayapparatus of FIG. 1;

FIG. 3 is a block diagram of an X-ray apparatus according to anexemplary embodiment;

FIG. 4 is a schematic diagram of an X-ray apparatus according to anexemplary embodiment;

FIG. 5 is a schematic diagram illustrating discharging of a lithium ionbattery according to an exemplary embodiment;

FIG. 6 is a schematic diagram illustrating charging of a lithium ionbattery according to an exemplary embodiment;

FIG. 7 is a schematic diagram of an X-ray apparatus according to anexemplary embodiment;

FIG. 8 is a schematic diagram of an X-ray apparatus according to anexemplary embodiment;

FIG. 9 illustrates a charger according to an exemplary embodiment;

FIG. 10 is a timing diagram of an operation of charging a lithium ionbattery according to an exemplary embodiment; and

FIG. 11 is a flowchart of a method of sensing of a low current state bya charger, according to an exemplary embodiment.

DETAILED DESCRIPTION

Certain exemplary embodiments are described in greater detail below withreference to the accompanying drawings.

In the following description, the same drawing reference numerals areused for the same elements even in different drawings. The mattersdefined in the description, such as detailed construction and elements,are provided to assist in a comprehensive understanding of exemplaryembodiments. Thus, it is apparent that exemplary embodiments can becarried out without those specifically defined matters. Also, well-knownfunctions or constructions are not described in detail since they wouldobscure exemplary embodiments with unnecessary detail.

The term “part” or “portion” used herein may be implemented usinghardware or software, and according to exemplary embodiments, aplurality of “parts” or “portions” may be formed as a single unit orelement, or one “part” or “portion” may include a plurality of units orelements. Expressions such as “at least one of,” when preceding a listof elements, modify the entire list of elements and do not modify theindividual elements of the list.

In the present specification, an image may include a medical imageobtained by a magnetic resonance imaging (MRI) apparatus, a computedtomography (CT) apparatus, an ultrasound imaging apparatus, an X-rayapparatus, or another medical imaging apparatus.

Furthermore, in the present specification, an “object” may be a targetto be imaged and may include a human, an animal, or a part of a human oranimal. For example, the object may include a body part (an organ,tissue, etc.) or a phantom.

FIG. 1 is an external view and block diagram of an X-ray apparatus 100implemented as a mobile X-ray apparatus, according to an exemplaryembodiment.

Referring to FIG. 1, the X-ray apparatus 100 according to the presentexemplary embodiment includes an X-ray radiation device 110 forgenerating and emitting X-rays, an input device 151 for receiving acommand from a user, a display 152 for providing information to theuser, a controller 120 for controlling the X-ray apparatus 100 accordingto the received command, and a communication unit 140, i.e., acommunication device or interface, for communicating with an externaldevice.

The X-ray radiation device 110 may include an X-ray source forgenerating X-rays and a collimator for adjusting a region irradiatedwith the X-rays generated by the X-ray source.

When the X-ray apparatus 100 is implemented as a mobile X-ray apparatus,a main body 101 connected to the X-ray radiation device 110 is freelymovable, and an arm 103 connecting the X-ray radiation device 110 andthe main body 101 to each other is rotatable and linearly movable. Thus,the X-ray radiation device 110 may be moved freely in athree-dimensional (3D) space.

The input device 151 may receive commands for controlling imagingprotocols, imaging conditions, imaging timing, and locations of theX-ray radiation device 110. The input device 151 may include a keyboard,a mouse, a touch screen, a microphone, a voice recognizer, etc.

The display 152 may display a screen for guiding a user's input, anX-ray image, a screen for displaying a state of the X-ray apparatus 100,and the like.

The controller 120 may control imaging conditions and imaging timing ofthe X-ray radiation device 110 according to a control command input bythe user and generate a medical image based on image data received froman X-ray detector 200. The controller 120 may control a position ororientation of the X-ray radiation device 110 according to imagingprotocols and a position of an object.

The controller 120 may include a memory configured to store programs forperforming the operations of the X-ray apparatus 100 and a processor ora microprocessor configured to execute the stored programs. Thecontroller 120 may include a single processor or a plurality ofprocessors or microprocessors. When the controller 120 includes theplurality of processors, the plurality of processors may be integratedonto a single chip or be physically separated from one another.

A holder 105 may be formed on the main body 101 to accommodate the X-raydetector 200. A charging terminal may be disposed in the holder 105 tocharge the X-ray detector 200. Thus, the holder 105 may be used toaccommodate and to charge the X-ray detector 200.

The input device 151, the display 152, the controller 120, and thecommunication unit 140 may be provided on the main body 101. Image dataacquired by the X-ray detector 200 may be transmitted to the main body101 for image processing, and then the resulting image may be displayedon the display 152 or transmitted to an external device via thecommunication unit 140.

The controller 120 and the communication unit 140 may be separate fromthe main body 101, or only some components of the controller 120 and thecommunication unit 140 may be provided on the main body 101.

The X-ray apparatus 100 may be connected to external devices such as aserver 31, a medical apparatus 32, and/or a portable terminal 33 (e.g.,a smart phone, a tablet PC, or a wearable device) in order to transmitor receive data via the communication unit 140.

The communication unit 140 may include at least one component thatenables communication with an external device. For example, thecommunication unit 140 may include at least one of a local areacommunication module, a wired communication module, and a wirelesscommunication module.

The communication unit 140 may receive a control signal from an externaldevice and transmit the received control signal to the controller 120 sothat the controller 120 may control the X-ray apparatus 100 according tothe received control signal.

Alternatively, by transmitting a control signal to an external devicevia the communication unit 140, the controller 120 may control theexternal device according to the transmitted control signal. Forexample, the external device may process data according to a controlsignal received from the controller 120 via the communication unit 140.

The communication unit 140 may further include an internal communicationmodule that enables communications between components of the X-rayapparatus 100. A program for controlling the X-ray apparatus 100 may beinstalled on the external device and may include instructions forperforming some or all of the operations of the controller 120.

The program may be preinstalled on the portable terminal 33, or a userof the portable terminal 33 may download the program from a serverproviding an application for installation. The server for providing anapplication may include a recording medium having the program recordedthereon.

FIG. 2 is an external view of the X-ray detector 200.

As described above, the X-ray detector 200 used in the X-ray apparatus100 may be implemented as a portable X-ray detector. The X-ray detector200 may be equipped with a battery for supplying power to operatewirelessly, or as shown in FIG. 2, may operate by connecting a chargeport 201 to a separate power supply via a cable C.

A case 203 maintains an external appearance of the X-ray detector 200and has therein a plurality of detecting elements for detecting X-raysand converting the X-rays into image data, a memory for temporarily orpermanently storing the image data, a communication module for receivinga control signal from the X-ray apparatus 100 or transmitting the imagedata to the X-ray apparatus 100, and a battery. Further, imagecorrection information and intrinsic identification (ID) information ofthe X-ray detector 200 may be stored in the memory, and the stored IDinformation may be transmitted together with the image data duringcommunication with the X-ray apparatus 100.

FIG. 3 is a block diagram of an X-ray apparatus 100 according to anexemplary embodiment.

Referring to FIG. 3, the X-ray apparatus 100 according to the presentexemplary embodiment may include an X-ray radiation device 305, acontroller 310, a power supply 320 including a lithium ion battery 322,and a charger 330. The X-ray apparatus 100 of FIG. 3 may be implementedas a mobile X-ray apparatus as shown in FIG. 1, and FIG. 3 illustratesonly components related to the present exemplary embodiment. Thus, asunderstood by those of ordinary skill in the art, the X-ray apparatus100 may further include common components in addition to those shown inFIG. 3.

The described-above with respect to the X-ray radiation device 110 andthe controller 120 of FIG. 1 may apply to the X-ray radiation device 305and the controller 310, respectively.

The power supply 320 may supply operating power to the X-ray radiationdevice 305 and the controller 310 via the lithium ion battery 322.Further, the power supply 320 may supply operating power to thecomponents of the X-ray apparatus 100 that require the operating power.For example, the power supply 320 may supply operating power to theinput device 151, the display 152, and the communication unit 140 of theX-ray apparatus 100 via the lithium ion battery 322.

The power supply 320 may control overcurrent that occurs during emissionof X-rays by the X-ray radiation device 305. In other words, as theX-ray radiation device 305 emits X-rays, overcurrent that is higher thana normal operating current may flow in the power supply 320, and thepower supply 320 may control the overcurrent. According to an exemplaryembodiment, in order to control overcurrent, the power supply 320 mayinclude a circuit consisting of a discharge field effect transistor(FET) and a charge FET connected in parallel. According to an exemplaryembodiment, in order to control the overcurrent, the power supply 320may include a circuit including current sensors having differentcapacities for measuring the amount of discharge current.

The charger 330 may charge the power supply 320. In detail, the charger330 may supply a charging power to charge the lithium ion battery 322 ofthe power supply 320. The charging power may be a power generated by thecharger 330. According to an exemplary embodiment, the charger 330 maybe combined with an external power supply to receive power from theexternal power supply. The charger 330 may then control the receivedpower according to a user input or arithmetic operations performedwithin the X-ray apparatus 100, to supply a charging power to thelithium ion battery 322.

The power supply 320, the charger 330, and the controller 310 may eachinclude a communication interface that enables communicationtherebetween. For example, the power supply 320, the charger 330, andthe controller 310 may communicate with one another via theircommunication interfaces according to a controller area network (CAN)protocol.

The power supply 320, the charger 330, and the controller 310 may eachbe separately embodied in a different module. Thus, the controller 310does not need to directly monitor a high voltage, and a high voltagecircuit is not needed within the controller 310. This may consequentlyreduce the risks associated with the high voltage circuit, therebyeffectively improving stability. When the power supply 320, the charger330, and the controller 310 are each composed of a different module,they may be used for different mobile X-ray apparatuses and thus share acommon platform. Further, by applying a shielded case to each separatemodule of the power supply 320, the charger 330, and the controller 310,it is possible to suppress Electro Magnetic Interference (EMI)/ElectroMagnetic Compatibility (EMC) noise that may occur therebetween.

FIG. 4 illustrates an X-ray apparatus 100 according to an exemplaryembodiment.

Referring to FIG. 4, a power supply 320 may include a lithium ionbattery 322, a battery management system (BMS) 410, a discharge FET 430,and a charge FET 440. FIG. 4 illustrates only components related to thepresent exemplary embodiment. Thus, one of ordinary skill in the artwill understand that the X-ray apparatus 100 may further include commoncomponents other than those shown in FIG. 4.

The lithium ion battery 322 is a type of secondary battery that includesa combination of a plurality of battery cells connected to each other.For example, the lithium ion battery 322 may include a total of 352cells, e.g., a serial connection of 88 cells which are connected inparallel as 4 strings, e.g., 4 parallel cell groups each including 88serially connected cells.

The BMS 410 may detect a state of the lithium ion battery 322, such as avoltage and a temperature thereof. According to an exemplary embodiment,the BMS 410 may include a battery stack monitor circuit designed tomonitor a voltage of the lithium ion battery 322 and a temperature of abattery cell. The BMS 410 may control and manage the power supply 320based on the state of the lithium ion battery 322. The BMS 410 maycontrol on/off states of the charge FET 440 and the discharge FET 430 tomanage a charge path and a discharge path, respectively.

The BMS 410 may operate a protection circuit based on the state of thelithium ion battery 322. In other words, the BMS 410 may operate theprotection circuit to protect the lithium ion battery 322. In detail,based on the state of the lithium ion battery 322, the BMS 410 mayoperate the protection circuit to protect the lithium ion battery 322against at least one of over-discharge, overcurrent, overheating, andunbalancing between battery cells.

The BMS 410 may operate the protection circuit when the lithium ionbattery 322 is in an over-discharged state where a voltage of thelithium ion battery 322 is lower than a reference voltage. For example,if a voltage of the lithium ion battery 322 drops to less than or equalto 275V, the BMS 410 may operate a shutdown circuit to turn itself off.The BMS 410 may operate the protection circuit when the lithium ionbattery 322 is in an overcurrent state where a current of the lithiumion battery 322 is higher than a reference value. For example, if thecurrent of the lithium ion battery 322 is greater than or equal to 40 A,the BMS 410 may operate a shutdown circuit to reset itself. The BMS 410may operate the protection circuit when the lithium ion battery 322 isin an overheated state where a temperature of the lithium ion battery322 is higher than a reference value. For example, if the temperature ofthe lithium ion battery 322 is greater than or equal to 70° C., the BMS410 may operate the protection circuit to shut off a charge path and adischarge path. Further, when the lithium ion battery 322 is unbalancedbetween cells, the BMS 410 may operate the protection circuit. Forexample, if a voltage difference between cells in the lithium ionbattery 322 remains greater than or equal to 1.5 V for 10 seconds ormore, the BMS 410 may operate a shutdown circuit to turn itself off.

The BMS 410 may communicate with a controller 310 via a communicationinterface 412, e.g., according to a CAN protocol. Further, the charger330 may communicate with the controller 310 via a communicationinterface 414, e.g., according to the CAN protocol. The BMS 410 maysupply a DC power to each component of the X-ray apparatus 100 includingthe controller 310.

The discharge FET 430 may include a plurality of FETs 432 connected inparallel. Since overcurrent may flow in the power supply 320 duringX-ray emission by the X-ray radiation device 305, the FETs having aspecific capacity in the discharge FET 430 may be connected in parallel.In other words, by connecting the FETs having the specific capacity inparallel, a maximum allowable current capacity of the discharge FET 430may be increased. For example, if overcurrent greater than or equal to300 A flows within the power supply 320 during X-ray emission by theX-ray radiation device 305, the discharge FET 430 may include 4 FETswhich are connected in parallel and have a capacity of 100 A each forthe protection against the overcurrent.

According to an exemplary embodiment, the discharge FET 430 and thecharge FET 440 may each include N-channel FETs.

The discharge FET 430 and the charge FET 440 may control a path ofdischarge or charge current when the lithium ion battery 322 isdischarged or charged. According to an exemplary embodiment, when thelithium ion battery 322 is discharged, the charge FET 440 is turned off,and a discharge current loop may be formed by the discharge FET 430.According to an exemplary embodiment, when the lithium ion battery 322is charged, the discharge FET 430 is turned off, and a charge currentloop may be formed by a diode or diodes 434 included in the dischargeFET 430 and the charge FET 440. Further, the lithium ion battery 322 maybe discharged and charged at the same time via the discharge FET 430 andthe charge FET 440.

While FIG. 4 shows that a load 406 for receiving a power from thelithium ion battery 322 includes the controller 310 and the X-rayradiation device 305, the load 406 may further include other componentsof the X-ray apparatus 100 that require power.

FIG. 5 is a schematic diagram illustrating discharging of a lithium ionbattery 322 according to an exemplary embodiment

When the lithium ion battery 322 is discharged, a charge FET 440 isturned off since a source (S) voltage of the charge FET 440 is higherthan a drain (D) voltage. Further, a discharge FET 430 is turned onsince a drain (D) voltage of the discharge FET 430 is higher than asource (S) voltage.

Thus, as shown in FIG. 5, a discharge current loop may be formed in aclockwise direction in which a discharge current flows through a load406, the discharge FET 430, and the lithium ion battery 322. Further,even when the charge FET 440 is turned off, discharging of the lithiumion battery 322 may be performed normally.

FIG. 6 is a schematic diagram illustrating charging of a lithium ionbattery 322 according to an exemplary embodiment.

When the lithium ion battery 322 is charged, a discharge FET 430 isturned off since a source (S) voltage of the discharge FET 430 is higherthan a drain (D) voltage thereof. When the discharge FET 430 is turnedoff, a charge current may flow through a diode 434 of the discharge FET430. Further, when the lithium ion battery 322 is charged, a charge FET440 is turned on since a drain (D) voltage of the charge FET 440 ishigher than a source (S) voltage thereof.

Thus, as shown in FIG. 6, a charge current loop may be formed in acounter-clockwise direction in which a charge current flows through acharger 330, the lithium ion battery 322, a diode 434 of the dischargeFET 430, and the charge FET 440. Further, even when the discharge FET430 is turned off, charging of the lithium ion battery 322 may beperformed normally.

FIG. 7 is a schematic diagram of an X-ray apparatus 100 according to anexemplary embodiment.

Referring to FIG. 7, a power supply 320 may include a lithium ionbattery 322, a BMS 410, a discharge FET 430, a charge FET 440, ashutdown circuit 710, a small-capacity current sensor 730, e.g., a firstcurrent sensor, a large-capacity current sensor 740, e.g., a secondcurrent sensor, a DC-to-DC (DC-DC) converter 720, and a fuse 760. TheX-ray apparatus 100 may include a charge current sensor 750, e.g., athird current sensor. Since the lithium ion battery 322, the BMS 410,the discharge FET 430, and the charge FET 440 respectively correspond tothe lithium ion battery 322, the BMS 410, the discharge FET 430, and thecharge FET 440 described with reference to FIG. 4, detailed descriptionsthereof will be omitted below.

The BMS 410 may detect current of the lithium ion battery 322 by usingthe current sensors having different capacities, i.e., the small-currentsensor and large-capacity current sensor 730 and 740. In detail, the BMS410 may detect current flowing in the lithium ion battery 322 by usingthe small-capacity current sensor 730. When overcurrent flows in thelithium ion battery 322, the BMS 410 may detect overcurrent flowing inthe lithium ion battery 322 by using the large-capacity current sensor740.

The BMS 410 may detect, via the small-capacity current sensor 730,current flowing in the lithium ion battery 322 by activating thesmall-capacity current sensor 730 while deactivating the large-capacitycurrent sensor 740. Then, when an X-ray radiation device 305 emitsX-rays, the BMS 410 may detect overcurrent that occurs during the X-rayemission via the large-capacity current sensor 740 by activating thelarge-capacity current sensor 740 while deactivating the small-capacitycurrent sensor 730. Subsequently, when the X-ray emission is completed,the BMS 410 may detect, via the small-capacity current sensor 730,current flowing in the lithium ion battery 322 by activating thesmall-capacity current sensor 730 while deactivating the large-capacitycurrent sensor 740. According to an exemplary embodiment, the BMS 410may receive an X-ray emission preparation signal from a controller 310and activate the large-capacity current sensor 740 to detect overcurrentoccurring during X-ray emission via the large-capacity current sensor740.

The BMS 410 may check the residual amount of the lithium ion battery 322based on the amount of current detected using the small-current sensorand large-capacity current sensor 730 and 740. In detail, the BMS 410may use Coulomb counting based gauging to check the residual amount ofthe lithium ion battery 322 based on the detected amount of current.

The X-ray apparatus 100 may further include the charge current sensor750 for measuring a charge current at an output terminal 752 of thecharger 330. When the lithium ion battery 322 is charged and dischargedat the same time, current measured by the small-current sensor andlarge-capacity current sensor 730 or 740 may be a sum of a dischargecurrent and a charge current. Thus, in order to accurately measure adischarge current and a charge current, the X-ray apparatus 100 maymeasure the charge current by using the charge current sensor 750.

The BMS 410 may receive signals indicating that the X-ray radiationdevice 305 starts emission of X-rays and that the X-ray radiation device305 completes the emission of X-rays from the controller 310 via acommunication interface 412.

The BMS 410 may turn itself off by using the shutdown circuit 710, e.g.,by using a switch included therein. When the BMS 410 may check a stateof the lithium ion battery 322 to detect hazardous conditions such asover-discharge and overcharge, the BMS 410 may turn itself off by usingthe shutdown circuit 710 that serves as a protection circuit. When theBMS 410 turns itself off, the power being supplied to the controller 310is also cut off, so that the controller 310 may turn off.

The fuse 760 is designed to stop continuous flowing of excessive currentthat is greater than a nominal value in the power supply 320 and mayprotect a battery cell when the lithium ion battery 322 is subjected toan external short circuit.

The DC-DC converter 720 may convert a voltage of the lithium ion battery322 into an operating voltage of the BMS 410 or a DC power of thecomponents of the X-ray apparatus 100.

FIG. 8 is a schematic diagram of an X-ray apparatus according to anexemplary embodiment.

Referring to FIG. 8, a power supply 320, a controller 310, and a charger330 may each include a communication interface and communicate with oneanother via their communication interfaces. For example, the powersupply 320, the controller 310, and the charger 330 may communicate withone another according to a CAN protocol.

The power supply 320 may include a BMS-only temperature sensor 820,e.g., a first temperature sensor. The BMS 410 may use the BMS-onlytemperature sensor 820 to monitor a temperature of the power supply 320and determine whether the power supply 320 is overheated. For example,if the power supply 320 is overheated to a temperature higher than aspecific threshold value, the BMS 410 may operate a protection circuitthat cuts off a charge path and a discharge path. As illustrated, theBMS-only temperature sensor 820 may include three sensors or threesensing points, but this is not limiting.

The power supply 320 may further include a controller-only temperaturesensor 810, e.g., a second temperature sensor, that may be directlymonitored by the controller 310. If a communication error occurs betweenthe controller 310 and the BMS 410, the controller 310 might not be ableto receive temperature information of the power supply 320 from the BMS410. The controller 310 may monitor the temperature of the power supply320 independently via the controller-only temperature sensor 810. Thus,when a communication error occurs, the controller 310 may determinewhether to turn off the BMS 410 by using the controller-only temperaturesensor 810 without a need to forcibly turn off the BMS 410.

The power supply 320 and the charger 330 may respectively include firstand second interrupt pins 831 and 833 that can be directly controlled bythe controller 310. The controller 310 may respectively transmit disablesignals to the power supply 320 and the charger 330 via the first andsecond interrupt pins 831 and 833, and accordingly turn off the powersupply 320 and the charger 330. Thus, when it is determined that atemperature of the power supply 320 is equal to or higher than aspecific threshold value via the controller-only temperature sensor 810,the controller 310 may forcibly turn off the power supply 320 and thecharger 330 via the first and second interrupt pins 831 and 833,respectively.

When the BMS 410 operates a shutdown circuit to turn itself off, ashutdown signal from the BMS 410 may be transmitted to the controller310. After receiving the shutdown signal, the controller 310 may monitorwhether the BMS 410 is shut down for a specific amount of time. If theBMS 410 is not shut down for the specific amount of time as a result ofmonitoring, the controller 310 may forcibly turn off the BMS 410 via thefirst interrupt pin 831. For example, after the BMS 410 activates ashutdown bit, the controller 310 may monitor whether the BMS 410 is shutdown for 10 seconds. If the BMS 410 is not shut down for 10 seconds, thecontroller 310 may forcibly turn off the BMS 410 via the first interruptpin 831.

FIG. 9 illustrates an X-ray apparatus according to an exemplaryembodiment.

According to an exemplary embodiment, the charger 330 may include awireless charging system including a transmitting module 920, e.g., atransmitter, and a receiving module 910, e.g., a receiver. For example,the charger 330 may be a self-inductive wireless charging system. In thecharger 330, the transmitting module 920 may convert an AC power from anexternal power supply into a DC power, amplify the DC power, andtransmit the amplified DC power wirelessly to the receiving module 910via a transmitting coil. The receiving module 910 may rectify thereceived power to charge the lithium ion battery 322.

As another example, the receiving module 910 of the charger 330 mayreceive a power transmitted wirelessly by the transmitting module 920installed externally to the receiving module 910 and may rectify thereceived power to charge the lithium ion battery 322. Thus, an X-rayapparatus 100 including the charger 330 may be located near thetransmitting module 920 and may charge the lithium ion battery 322 byusing the power transmitted wirelessly by the transmitting module 920.

FIG. 10 is a timing diagram of an operation of charging a lithium ionbattery 322 according to an exemplary embodiment.

First, during interval A, as the charger 330 performs a chargingoperation, a charge voltage may increase while a charge current remainsconstant.

Thereafter, during interval B, as the lithium ion battery 322 relaxes,the charge current may decrease.

An interval C indicates a low current state in which a charge currentless than a specific threshold value remains for a specific amount oftime. The charger 330 may detect the low current state, as will bedescribed in detail below with reference to FIG. 11. If the low currentstate is detected for a specific amount of time or a specific number oftimes, the charger 330 may stop a charging operation. For example, ifthe charger 330 detects a low current state, in which the charge currentis less than or equal to 0.5 A, 10 times, the charger 330 may stop acharging operation. Thus, if the lithium ion battery 322 relaxes, thecharger 330 may stop the charging operation, thereby preventingunnecessary power consumption.

Subsequently, during interval D, when a voltage of the lithium ionbattery 322 drops to a preset value, the charger 330 may restart thecharging operation, and the charge current may also increase.

Thereafter, during interval E, which corresponds to the interval A, asthe charger 330 performs the charging operation, the charge voltage mayincrease while the charge current remains constant.

FIG. 11 is a flowchart of a method of sensing of a low current state bythe charger 330, according to an exemplary embodiment.

The charger 330 may detect a charge current value (operation S1101).

The charger 330 may determine whether the detected charge current valueis less than an upper off-state charge current threshold (operationS1103). For example, the upper off-state charge current may be 0.5 A.

If the detected charge current value is less than the upper off-statecharge current threshold in operation S1103, the charger 330 mayincrease a low current count value by 1 (operation S1105). In otherwords, if the low current count value is increased by 1 each cycle toreach a certain count value, e.g., 10, the charger 330 may determinethat the current has remained low for a certain amount of time.

Otherwise, if the detected charge current value is not less than theupper off-state charge current threshold in operation S1103, the charger330 may determine whether the detected charge current value is greaterthan a lower on-state charge current threshold (operation S1107). Forexample, the lower on-state charge current threshold may be 0.8 A.

If the detected charge current value is greater than the lower on-statecharge current threshold in operation S1107, the charger 330 may set thelow current count value to 0 (operation S1109).

Otherwise, if the detected charge current value is not greater than thelower on-state charge current threshold in operation S1107, the charger330 may detect a charge current value (operation S1101).

The charger 330 may determine whether the low current count value isfive 5 (operation S1111).

If the low current count value is 5 in operation S1111, the charger 330may generate a signal indicating that a charging operation is to bestopped after a lapse of a certain amount of time (operation S1113).

Otherwise, if the low current count value is not 5 in operation S1111,the charger 330 may determine whether the low current count value is 10(operation S1115).

If the low current count value is 10 in operation S1115, the charger 330may stop the charging operation (operation S1117). In other words, ifthe low current count value is 10, the charger 330 may determine thatthe low current state has remained for the certain amount of time andthen stop the charging operation.

Otherwise, if the low current count value is not 10 in operation S1115,the charger 330 may detect a charge current value (operation S1101).

Exemplary embodiments may be implemented through non-transitorycomputer-readable recording media having recorded thereoncomputer-executable instructions and data. The non-transitorycomputer-readable medium may include a compact disc (CD), a digitalversatile disc (DVD), a hard disc, a Blu-ray disc, a universal serialbus (USB), a memory card, a read only memory (ROM), and the like. Theinstructions may be stored as program codes, and when executed by aprocessor, may generate a predetermined program module to perform aspecific operation. When being executed by the processor, theinstructions may perform specific operations according to the exemplaryembodiments.

The foregoing exemplary embodiments and advantages are merely exemplaryand are not to be construed as limiting. The present teaching can bereadily applied to other types of apparatuses. The description ofexemplary embodiments is intended to be illustrative, and not to limitthe scope of the claims, and many alternatives, modifications, andvariations will be apparent to those skilled in the art.

What is claimed is:
 1. A mobile X-ray apparatus comprising: an X-ray radiation device configured to emit X-rays; a controller configured to control the X-ray radiation device; a power supply configured to supply operating power to the X-ray radiation device and the controller; and a charger configured to charge the power supply, and wherein the power supply comprises: a lithium ion battery including a plurality of battery cells, a current sensor configured to detect current of the lithium ion battery, and a battery management system (BMS) configured to detect an occurrence of an overcurrent in the lithium ion battery via the current sensor in response to receiving an X-ray emission preparation signal, and to control the overcurrent that occurs during emission of X-rays.
 2. The mobile X-ray apparatus of claim 1, wherein the power supply further comprises a temperature sensor configured to detect a temperature of the power supply, and wherein the BMS is further configured to control a charge current path to be an off-state based on the temperature detected by the temperature sensor being higher than a threshold value.
 3. The mobile X-ray apparatus of claim 2, wherein the BMS is further configured to control an on-state or an off-state of a discharge current path in which a discharge current flows from the lithium ion battery to the controller and the X-ray radiation device, and wherein the power supply is further configured to supply the operating power to the X-ray radiation device and the controller via the discharge current path being in the on-state.
 4. The mobile X-ray apparatus of claim 2, wherein the power supply further comprises a charge switch connected to the charger and configured to be turned on and off, and based on the charge switch turned on, the charge current path in which a charge current flows from the charger to the lithium ion battery is in an on-state.
 5. The mobile X-ray apparatus of claim 4, wherein the power supply further comprises a discharge switch connected to the lithium ion battery and used to form a discharge current path, and wherein the discharge current path is a current path in which a discharge current flows from the lithium ion battery to the controller and the X-ray radiation device.
 6. The mobile X-ray apparatus of claim 5, wherein the discharge switch includes a plurality of FETs connected in parallel to one another.
 7. The mobile X-ray apparatus of claim 5, wherein the BMS is further configured to detect a state of the power supply, to control the charge current path by turning off the discharge switch and turning on the charge switch, and control the discharge current path by turning on the discharge switch and turning off the charge switch.
 8. The mobile X-ray apparatus of claim 1, wherein the power supply further comprises: a temperature sensor configured to detect a temperature of the power supply, wherein the temperature sensor is directly monitored by the controller.
 9. The mobile X-ray apparatus of claim 1, wherein the BMS is further configured to control an operation of a protection circuit for protection against at least one from among an over-discharge, the overcurrent, an overheating, and an unbalance between at least two cells among the plurality of battery cells included in the lithium ion battery.
 10. The mobile X-ray apparatus of claim 1, wherein the current sensor includes a first current sensor configured to detect a first current, and wherein the BMS is further configured to detect a value of the overcurrent in the lithium ion battery via the first current sensor in response to receiving the X-ray emission preparation signal.
 11. The mobile X-ray apparatus of claim 10, wherein the power supply further includes a second current sensor configured to detect a second current smaller than the first current.
 12. The mobile X-ray apparatus of claim 1, wherein each of the controller, the power supply, and the charger includes a respective communication interface, and the controller, the power supply, and the charger are configured to communicate with one another via the respective communication interface.
 13. The mobile X-ray apparatus of claim 12, wherein the respective communication interface performs communication according to a controller area network (CAN) protocol.
 14. The mobile X-ray apparatus of claim 1, wherein the charger includes a wireless charging system including, a transmitter and a receiver.
 15. The mobile X-ray apparatus of claim 1, wherein the charger is further configured to receive power wirelessly from an external device and charge the lithium ion battery based on the received power.
 16. The mobile X-ray apparatus of claim 1, wherein the power supply further comprises: a shutdown circuit configured to turn off the BMS; a discharge switch connected to the lithium ion battery and used to form a discharge current path; and a charge switch connected to the charger and configured to turn on and off to charge the lithium ion battery.
 17. A mobile X-ray apparatus comprising: an X-ray radiation device configured to emit X-rays; a controller configured to control the X-ray radiation device; a power supply configured to supply operating power to the X-ray radiation device and the controller; and a charger configured to charge the power supply, and wherein the power supply comprises: a lithium ion battery including a plurality of battery cells, a current sensor configured to detect current of the lithium ion battery, a temperature sensor configured to detect a temperature of the power supply, and a battery management system (BMS) configured to detect an occurrence of an overcurrent in the lithium ion battery via the current sensor in response to receiving an X-ray emission preparation signal, and wherein, the controller is further configured to directly monitor information about the temperature of the power supply detected by the temperature sensor. 